432 Support upgrade for existing RGs with Init Container

[santhoshatdell]

Description

Replication APIs are updated from v1alpha1 to v1 (#75).
Changes in this PR are related to Init Container which migrates the existing RG's apiVersion & CRD's to v1 during upgrade.
For fresh installations, init container will not do anything as no existing RGs will be found.

To follow-up:

• Base image may need to be changed. Currently bitnami/kubectl is used.
• Need new Docker Hub repository for new image (dellemc/dell-replication-init).

GitHub Issues

List the GitHub issues impacted by this PR:

GitHub Issue #
dell/csm#432

Checklist:

• I have performed a self-review of my own code to ensure there are no formatting, vetting, linting, or security issues
• I have verified that new and existing unit tests pass locally with my changes
• I have not allowed coverage numbers to degenerate (81.8%)
• I have maintained at least 90% code coverage
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have maintained backward compatibility (via Init Container which will migrate RG & CRD versions during upgrade. With that, existing RGs continue to work).

How Has This Been Tested?

• Installed CSM 1.5 replication module with isilon driver, and provisioned few PV/RGs.
• Upgraded isilon & replicator sidecar images to latest on both k8s clusters.
  cd dell-csi-helm-installer && ./csi-install.sh --namespace isilon --values /home/santhosh/my-samples/csm-replication/isilon-values.yaml --upgrade
• Upgraded replication-controller images.
  ./repctl create -f ../deploy/controller.yaml
• Verified RGs and CRD for v1 version with init container logs and kubectl on both clusters.
• Deleted target PowerScale SyncIQ policies.
• Restarted pod to confirm no migration was run second time.
• Provisioned new RG and ran replication actions on existing & new RGs.

[harshaatdell]

Thank you

[tdawe]

The ubi-minimal image can be used as a base image, since that will be required for operator certification. In this case, you would need to install the kubectl binary during image creation. See here for reference to the current ubi-minimal image that is being used: https://github.com/dell/csi-powerflex/blob/main/overrides.mk#L6

[santhoshatdell]

We got to know about the base image requirement recently. @donatwork is currently working on common dell/kubectl image which we can switch to as needed.
If the init container is going to be around for few releases, I am not sure if it has to be certified. Moreover, rest of the replication images are built with scratch. When we must switch all images to use ubi-minimal as base, I can work on converting all at that time.

[rbo54]

I agree with Trevor's comments on semantic versioning and ubi-minimal. I didn't find anything additional.